Signaling system



-Jan( 11, 1927.

G. A. LOCKE SIGNALING SYSTEM Filed March 1,. 1

' /n van/0r: Georgefliocke Patented 1:11.111,

UNITED STATES' PATENT OFFICE.

GEORGE A. LOGKE, OF GLEN COTE, NEW YORK, A SSIGNOB 11'0 WESTERN ELECTBIG comm, INCORPORATED, OF NEW Y O BK, N. .Y., A.('JORPOBA'JYION 01' NEW YORK.

srenanme srsrnrr.

Application filed March 1, 1824. Serial No. 686,188.

This invention relates to signaling systems and particularly to synchronous telegraph systems.

It is an object of the invention tomaintain synchronism of the apparatus associated with the.line during a brief interval when no impulses are transmitted over the line. Such an interruption may be due to-a temporary opening of the line, to a steady app ication of potential as occurs in aline swing, or it may occur in the normal-operation of a system in which it is desired to change the direction of transmission.

To accomplish this object and in accord-l ance with the features of the invention, means is provided at the respective stations cooperating with the correcting system to mamtainap roximate synchronism during the interval m which no impulses are trans mitted over the line. This and other fea tures ofthe invention may be more clearly understood by reference to the accompany ing drawing which discloses one embo iment of the invention.

Referring to this drawing, the invention is shown in connection with a signaling systern provided with means for automatically reversing the direction of transmission over the line. The system per se is not a part of the present invention but is described in detail and claimed in an application of Allison A. Clokey, Serial No. 592,216, filed October 4, 1922. Y

Each end of the cable is provided with a distributor comprising a sending face S, a receiving face R and a correcting face C, the brush arms A, B and D associated therewith being driven in the well known manner by means of an im ulse motor E controlled by a driving fork The two distributors at either end of the cable are maintained in synchronism b means of the electrical correction metho art comprisin rector relay and a resistance I which is in series with the driving magnet of fork F. Transmission is accomplished in the usual manner by a perforated tape controlled transmitter K operatin in conjunction with the sending face of'the distributor.

which is well known in the an impulse relay G, a cor- The line impulses are received on a line relay M after passing through the amplifier O and are repeated mto the printing'relay N which operates in conjunction wlth the receiving face R of the distributor to distribute the received im ulses to the roper selecting magnets of are printer in a manner which is readily understood by those skilled in the art.

The distributor shaft 5 is employed to drive a cam shaft 6 carrying cams 7 and 8 through a train of reduction gears 9 in the diametrically opposite each other. The.

cams 7 and 8 are positioned on shaft 6 so that the raised portion of cam 8 enga es spring 12 a certain time interval before 51c raised portion of cam 7 enga es spring 16. This time interval is dependint upon the lag of the cable, the lag of the apparatus and the amplifier shock and in practice is of the order of four seconds.

Contact spring 13 is connected to segment 18 on sending face S and once in each revolution of brush arm A is connected by the inner brush to common ring 19 which is connected through the winding of polarized relay 20 to ground. In a similar manner, contact spring 17 is connected to segment 21 on receiving face R and is connected by the inner brush of arm Bto common ring 22 which in turn is connected to round through the windings of polarized re ay 23. Upon the energization of relay 20 its armature engages contact 25 thereby completing an energizing circuit from battery 26 through the winding of transmitter control relay 27. A resistance 28 is bridged across the winding of relay 27- to make it slow acting. Upon the energization of relay 23 its armature engages contact 29 thereby completing an energizintg circuit from battery to the winding 0 receiver control relay 31. The line or cable is connected to armature 32 of relay 27 and in the position shown armature 32 is in engagement with nected to one terminal of correcting resistance I, thus rendering the correcting apparatus'inoperative. n its operated position armature 40 enga es contact which is joined to contact 47 o relay 31.

Referrin to receiver control rela 31, armature 42 is adapted to engage eit er contact 43 or contact 44 thus connecting either positive or negative battery to s ing 16. Armature 46 is connected throug the v1- brating winding of corrector rela H, common rm 48 of correcting face which is alternate y connected by means of outer brush of arm A and se mental rin 50 to the positive terminal 0 grounded attery 51 or the negative terminal of grounded battery 52. The resistance elements 54 and 55 are provided to prevent short-clrcuitlng the batteries when the brush bridges adJacent segments. The midpoint of corrector relay H is connected to grounded battery 56 while the outer terminals are connected respectively to the sets of alternate contacts on segmental ring 57 whlch is connected by means of inner brush of arm D and common ring 58 to the armature of impulse relay G.

In the operation of the system, the station shown is operating as the sending station and impulses are being transmitted to the cable from transmitter K through rings 34 and 35 of sending face S, contact 33 and armature 32 of relay 27. The receivin .apparatus is disconnected from the cab e at contact 36. Since armature 40 is in engagement with contact 41, the resistance I is grounded at either end thus rendering the correcting apparatus inoperative and making this station the pace setting station. The transmitter K continues to transmit signal impulses until the raised portion of cam 8 moves spring 12 into engagement with spring 13 thus connecting the positive terminal of grounded battery through contact 38, armature 37, springs 12 and 13 to segment 18. As the inner brush of brush arm A engages segment 18, the circuit is extended through common ring 19 and polarized relay- 20 to ground. Relay 20 is thus energized tion 10 has rotated an amount suflicient to open the circuit between springs 12 and 13. As armature 40 moves awa from contact 41 and engages contact 45, t e short circuit around resistance 1 is removed and a circuit is completed from grounded armature 40 through contact 45, contact 47 and armature 46 of relay 31, the vibratingwinding of corrector relay H, common ring 48 of correcting face C and then alternately through the segments of segmental ring 50 to positive and negative batteries 51 and 52, respectively. The armature of corrector relay H is thus caused to vibrate in accordance with the movements of brush arm D over segmental ring 50 thus alternately connecting resistance I in and out of circuit with the driving magnet of fork F and thereby maintaining the synchronism at a mean point between the maximum and minimum values. This operation continues for a time suflicient to al low for the lag of the apparatus and cable and the time required to permit the amplifier to function properly at which time the raised portion 14 of cam 7 moves the cam s ring 16 into engagement with spring 17. A circuit is thus completed from the positive terminal of a grounded battery through contact 43, armature 42, springs 16 and 17 to segment 21 of receiving face B. As the brush arm B rotates, the inner brush completes a circuit from segment 21 to common ring 22 and thence to ground through the winding of olarized relay 23. The operation of this re ay closes a circuit 'from battery 30, through the armature and contact of relay '23 and the winding of receiver control relay 31, causing the operation of the latter. Armature 42 moves from contact 43 to contact 44 thus imressing a negative potential on spring 16. owever, by the time this action takes place, springs 16 and 17 are separated and no further action takes place until the raised portion 15 moves into engagement with spring 16. As armature 46 moves away from contact 47, the vibrating circuit through corrector relay H is interrupted, thus permit-Y ing the normal operation of corrector relay H in conjunction with segmental ring 57 and common ring 58, and causing the station to now operate as the controlled station. Simultaneously, armature 60 of relay 31 moves into engagement with contact 61 thus connecting the armature of printing relay N throu h armature 60, contact 61 to thecommon ring62 of receiving face R and thence by the outer brush of arm B to the receiving segments and to the magnets of printer P.

This station now 0 crates as a receiving station until the raise portion 11 of cam 8 has rotated to a point w ere it engages cam spring 12 and moves it mto en agement with spring 13. A circuit is then 0 osed from the negative terminal of grounded battery, through contact 39 and armature 37 of relay 27, s rin s 12 and 13 to segment 18 of sending dice Upon the next revolution of brush arm A, a circuit is completed through the inner brush and common ring 19 and t e winding of polarized relay 20 to ground. The armature of relay 20 1s thus energized and opens the operating circuit of transmitter control relay 27 causin the armatures of this relay to fall back an again assume the position shown in the drawing, thus again connecting the transmitting ap aratus to the cable and changing the station the pace setting station b the short-circuitlng of resistance I. A ew seconds later the raised portion 15 of cam 7 causes spring 16 to engage spring 17 thus completing an operating circuit for polarlzed relay 23 from the ne ative terminal of grounded battery throug contact 44, armature 42 springs 16 and 17, segment 21, inner brush and common ring 22 of receiving face B through the winding of relay 23 to ground. 'lhe o ration of relay 23 causes the opening 0 the operating circuit for relay 31, allowing its armature to fall back into the position shown thus disconnecting the rinting mechanism and permitting the station to again operate as a transmitting station until the raised portion 10 of cam 8 again engages with cam spring 12.

What is claimed is:

1. A signaling system comprlsmg a hne over which signahng impulses are transmitted, synchronous apparatus associated therewith and means effective only upon the cessation of signaling impulses to maintain substantial synchronism during a period in which no impulses of any kind are transmitted over the line.

2. A signaling system comprising a l ne, synchronous apparatus associated therewith,

correcting means responsive to line signals for maintainin said apparatus in synchronism, and furt er means for supplying correcting impulses during an interval when no impulses of any kind are transmitted over the line.

3. A si naling system comprising a line over whic signaling impulses are transmitted, synchronous apparatus associated therewith, correcting means res onsive to line signals for maintaining sync ronism, means for rendering said corrective means moperative. and additional means effective only upon'the cessation of signalin impulses for maintaining. substantia s nc romsm during the period when said rst means is rendered inoperative.

4. A signaling 5 stem 'comprisin a line, synchronous distri utors associate therewith, means for reversing the direction of transmission over said line, and'means independent of current impulses transmitted over the line for maintaining substantial synchronism during the interval required for said reversal. I

5. A signaling s stem comprisin a line, synchronous distributors associate therewith, means for reversing the direction of transmission over said line, and means cooperating with said distributors and independent of current impulses transmitted over the line for maintaining substantial synchronism during the interval required for said reversal.

6. In a signaling system arranged for periodically reversing the direction of transmission, a line interconnecting a plurality of stations, receiving and transmitting apparatus at each of said stations, means at each station for disconnecting the transmitting apparatus from the line, means for subsequently connecting the receivin apparatus to the line, and means'independent of current impulses transmitted over the line for maintainin substantial s nchronism during the interva intervening lietween the operation of said first and second means.

7. In a signaling system arranged for pcriodically reversing the direction of transmission, a line interconnecting a plurality of stations, receiving and transmitting apparatus at each of said stations, means at each station for disconnecting the transmitting apparatus from the line, means for connecting the receiving apparatus to the line a given time interval after the operation of said first means, and means for maintaining substantial synchronism during the interval intervening between the operation of said first andsecond means.

8. In a signaling system, a line over which signaling impulses are transmitted, means for reversing the direction of transmission over the line, rotary distributors associated with the line, means for maintaining said distributors in synchronism, and additional means effective only during the period of.

reversal and independent of any impulses transmitted over the line for maintaining the distributors in ap roximate synchronism during such period.

9. .In a signaling system, a line over which signaling impulses are transmitted, synchronous apparatus associated therewith, correcting means responsive to signaling impulses for maintaining synchronism, and means for supplying correcting impulses to said correctin means durin an interval when no impuFses of any kin are transmitted over the line.

10. In a signaling system in which synchronism is normal y controlled by the operation of a' correcting relay in response to signal impulses transmitted over the line, the method of maintaining synchronism during an interval when no current im- Lemme ulses of. any kind are transmittal over the 30 inc, which consists in en plying alternate positive and ne ative impu ses to control the operation of t e correcting relay during such interval.

In witness whereof, I hereunto subscribe 15 my name this 29th day of February A. D.,

GEO RGE A. LOCKE. 

